Drink drivers stopped before they start

Repeat drink drivers will soon be forced to have a device installed in their cars which stops them from driving if they've been drinking.

Associate Transport Minister Craig Foss made the announcement on Parliament's forecourt on Tuesday afternoon, saying the interlock devices could mean between 4000-5000 people could have them installed because of the new law.

The AA says the devices - in-car breathalysers - have already been proven to work. The device won't let the car start unless the driver passes the test.

(Alex Baird / Newshub.)

They've been a sentencing option for judges since 2012.

"Interlocks have prevented 4137 drink drive attempts since 2013. That is 100 drink drive attempts prevented each month with only a couple of hundred interlocks in use across New Zealand," says AA spokesman Dylan Thomsen.

Installing more could have a major impact.

"More interlocks will mean less drink driving and less innocent people put at risk."

The AA says only 2 percent of eligible offenders have been forced to use an interlock so far, the result of a "combination of issues". It had been campaigning to make the devices compulsory.

"Alcohol interlocks are the best weapon we have in the fight against drink driving, and this change will see them used much more by the courts," Mr Thomsen says.

Under the changes, Mr Foss says anyone convicted of two or more drink driving offences within five years, and any first-time offenders caught driving more than 3.2 times the legal alcohol limit, will be forced to use one.